Not All Bats Land The Same Way

Date:

March 21, 2009

Source:

Brown University

Summary:

Scientists have documented for the first time how bats land. The results are surprising: not all bats land the same way. The findings could offer new insights into how the second-largest order of mammals evolved.

Share:

Total shares:

FULL STORY

Bat on Arrival. A Brown University-led team has discovered that bats land differently depending on the roosting site in a first-ever video documentation.

Credit: Image courtesy of Brown University

Bat on Arrival. A Brown University-led team has discovered that bats land differently depending on the roosting site in a first-ever video documentation.

Credit: Image courtesy of Brown University

People have always been fascinated by bats, but the scope of that interest generally is limited to how bats fly and their bizarre habit of sleeping upside down. Until now, no one had studied how bats arrive at their daytime perches.

A Brown University-led research team is the first to document the landing approaches of three species of bats — two that live in caves and one that roosts in trees. What they found was surprising: Not all bats land the same way.

“Hanging upside down is what bats do,” said Daniel Riskin, a postdoctoral researcher in the Ecology and Evolutionary Biology department at Brown and lead author on a paper published in the Journal of Experimental Biology. “We've known this. But this is the first time anyone has measured how they land.”

Using sophisticated motion capture cameras in a special flight enclosure, the team filmed each species of bat as it swooped toward a latticed landing pad and landed on it. Cynopterus brachyotis, a tree-roosting bat common in tropical parts of southeast Asia, executed a half-backflip as it swooped upward to the landing site, landing as its hind legs and thumbs touched the pad simultaneously — a four-point landing, the group observed.

The landing is hard, Riskin noted, with an impact force more than four times the species’ body weight.

The team then turned its attention to two cave-roosting species, Carollia perspicillata and Glossophaga soricina. These bats, common in Central and South America, approach their landing target with a vertical pitch and then, at the last instant, yaw to the left or to the right — executing a cartwheel of sorts — before grasping the landing pad with just their hind legs.

The two-point landing is much gentler than the impact force exerted by the tree-roosting bats, the researchers observed; the cave-roosting bats have a landing impact force of just one-third of their body weight.

There are about 1,200 recognized bat species worldwide, so Riskin was cautious about not drawing any grand conclusions. Still, he said, the fact that the team has documented that bats land differently could open new insights into a species that makes up roughly one-fifth of all mammals on earth.

Other Brown researchers who worked on the paper include Sharon Swartz, associate professor of biology; Tatjana Hubel, a postdoctoral researcher; and Joseph Bahlman, a graduate student. John Ratcliffe, a biologist at the University of Southern Denmark, and Thomas Kunz, a biologist at Boston University, contributed to the paper.

The research was funded by the U.S. National Science Foundation, The U.S. Air Force Office of Scientific Research, Sigma Xi in the United States, The Natural Sciences and Engineering Research Council of Canada, and the Danish Natural Sciences Research Council.

Story Source:

The above post is reprinted from materials provided by Brown University. Note: Materials may be edited for content and length.

July 31, 2015  Resettlement projects in the Amazon are driving severe tropical deforestation, according to new research. Widely hailed as a socially responsible and 'innocuous' strategy of land redistribution, ... read more

July 29, 2015  Viewing aquarium displays led to noticeable reductions in blood pressure and heart rate, a research team found in the first study of its kind. They also noted that higher numbers of fish helped to ... read more

July 31, 2015  A new study examines how consuming the concentrated extract of thylakoids found in spinach can reduce hunger and cravings. Thylakoids encourage the release of satiety hormones, which is very ... read more

July 30, 2015  The behavior of fruit flies, which are commonly used in laboratory experiments, is altered by electric fields, new research shows. The research indicates that the wings of the insects are disturbed ... read more

July 31, 2015  Starvation early in life can alter an organism for generations to come, according to a new study in nematodes. The epigenetic effects are a 'bet-hedging strategy.' Famine survivors are smaller and ... read more

July 31, 2015  The humble butterfly could hold the key to unlocking new techniques to make solar energy cheaper and more efficient, pioneering new research has shown. By mimicking the v-shaped posture adopted by ... read more

Jan. 8, 2015  When bats hunt in groups at night, they rely on the sounds of their fellow bats to tip them off on the best places to a grab a good meal. Researchers reporting their findings are calling this ... read more

Dec. 4, 2014  In a discovery that overturns conventional wisdom about bats, researchers have found that Old World fruit bats -- long classified as 'non-echolocating' -- actually do use a rudimentary form ... read more

May 26, 2010  Many species of bats hunt insects "on the wing" by making ultrasonic calls and using the echo to find prey while in flight. But do bats use echolocation calls to communicate with each other ... read more